Why do green plants grow the best under red/violet-blue?

Question

i found my plants grow fastest under the red/orange color the fastest. Please explain me this in terms of wavelength.

Red = longest wavelength

Violet-Blue = shortest wavelength

Eventhough they are complete opposites, why do they BOTH (not one) work the best for green plants?

Why is it that Red is a warm color than the Violet? (Violet surely carry more energy; higher frequency, E= v X Plank's Constant).

Answer 1

Blue light is absorbed less efficiently than red due to higher energy.

Also, blue and red photons do different things within the cell. ie. they set off different sets of chemical reactions like controlling the circadium rhythm (red light at dawn, blue light at dusk etc.).

Chlorophyll a prefers red light over blue (although blue is preferred almost as much). Most plants have a higher ratio of chlorophyll a to b.

Plant wants to use all of the light to maximize energy absorption. They also have other pigments to absorb at other wavelengths.

This website lists some info on the blue and red action spectrums

http://www.biology-online.org/biology-fo...

red is warm compared to violet cause red wavelength is just "above" infrared (thermal radiation)

Answer 2

In general plants use red and blue light for photosynthesis. Of the two Red is used the most.